Gross Reservoir
Expansion Project


Gross Reservoir
Expansion Project


This short video summarizes Denver Water’s community commitments based on years of study and robust outreach to Gross Reservoir neighbors. Also, read more on our Community Responsiveness page and on !

Jeff Martin, Denver Water’s program manager on the Gross Reservoir Expansion Project sits for an interview about the project goals, core values and minimizing inconvenience to our neighbors.

Environmental Commitments

Provide $2 million towards aquatic habitat improvements on the Upper Colorado River.

Provide $1 million to the Upper Colorado River Wild and Scenic Management group to fund flow-related projects to protect the outstanding and remarkable values within segments of the Upper Colorado River.
Provide $6 million to Grand County to use towards environmental projects, and continue to participate in the “Learning By Doing” collaborative effort, which has already resulted in tangible positive environmental impacts on the West Slope.

Construct and maintain sediment pond on Berthoud Pass to keep the Fraser River bottom clean. Check out, “Good for drivers, bad for the Fraser River.”

Restore a portion of Fraser Flats in Grand County. Check out, “Keep it cool: Good for the Fraser River and its trout.”

Release water into Ranch Creek in response to high temperatures found through water temperature monitoring. Check out, “Searching for solutions to help trout keep their cool.”

Monitor stream temperatures and water quality in Gross Reservoir, South Boulder Creek and the Fraser River Basin.

Provide funding towards Colorado Parks and Wildlife’s cutthroat trout habitat projects to protect and restore native trout populations.

Through a cooperative process, replace culverts on Fraser River, Cabin Creek and St. Louis Creek with aquatic organism passage culverts that will enable free passage of fish and other aquatic organisms.

Provide flushing flows in the Williams Fork and Fraser River basins.

Provide more than 1,000 acre-feet of water in Grand County for environmental purposes.

Complete a stream restoration project on South Boulder Creek.

Create an environmental pool in Gross Reservoir that will be managed by the Cities of Boulder and Lafayette to provide flows into South Boulder Creek during periods of low or no flows.

Allow Grand County to store up to 2,500 acre-feet of water in Williams Fork Reservoir for environmental purposes.

Complete a stream restoration project on the Williams Fork River.

Begin stream bank monitoring on the North Fork of the South Platte River and South Boulder Creek to identify erosion and/or unstable banks, and make repairs, as needed.

Construct a fish ladder on Cabin Creek in Grand County.

Convey approximately 540 acres of land near the Moffat Tunnel to the U.S. Forest Service for permanent protection and management as part of the National Forest System.

Protect raptor species, fight invasive species, relocate rare plant species and responsibly remove trees and brush in the reservoir’s expanded footprint.

Continue to participate in the U.S. Fish and Wildlife Service’s Upper Colorado River Recovery Program and the Platte River Recovery Implementation Program, both designed to protect endangered species.

Progress and Schedule

Coffee Shop Office Hours

The Public Information Yurt is closed for the winter season. We continue office hours at Coal Creek Coffee located at 30509 Highway 72.

Upcoming office hours are below.

Tuesday, February 25: 10:30 a.m. to 1 p.m.

Please stop by to learn more about the Gross Reservoir Expansion Project. For local community members that are not able to visit during these times, please reach out to us to schedule an appointment outside of our office hours posted above.


Denver Water makes way for toads

TAP - Dec. 2, 2019 - "Denver Water, as part of an expansive environmental agreement with the Arapaho-Roosevelt National Forest, recently completed its first “toad tunnel” under Vasquez Creek Road just outside Winter Park." Read the full story here.

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Indoor ‘waterfall’ puts water to the test at CSU

TAP - October 2, 2019 - “It’s a fun job and also extremely important to the communities where these structures are built,” said Chris Thornton, director of the Colorado State University Hydraulics Laboratory. “Our job is to provide designers with information to make...

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Beautiful weather and great cookout!

On Saturday, September 28 Denver Water hosted the fifth community cookout at the Gross Reservoir Expansion Project public information yurt. We enjoyed meeting new visitors to the yurt and were happy to see some returning guests to hear about the latest project...

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Fact or Fiction

GIS Interactive Map

Thank You Supporters